Means for controlling electric boosters



No. 750,972. PATENTED FEB. 2, 1904.

E. M. HEWLETT. MEANS FOR CONTROLLING ELEGTRIO-VBOOSTERS.

APPLICATION FILED AUG. 31, 1900 N0 MODEL.

. in 9 A l Witnesses Inventor.

Edward M. Hewlett to temporary or periodical increase of load.

UNITED STATES Patented February 2, 1904.

PATENT OFFICE.

EDWARD M. HEWLETT, OF SCHENECTADY, NEIV YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEIV YORK.

MEANS FOR CONTROLLING ELECTRIC BOOSTERS.

SPECIFICATION forming part of Letters Patent No. 750,972, dated.February 2, 1904,

Application filed August 31, 1900.

To all whom, it may concern.-

Be it known that I, EDWARD M. HEWLETT, a citizen of the United States,residing at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements in ControllingElectric Boosters, of which the following is a specification.

In operating constant-potential systems it is frequently desirable toraise the potential on particular feeders either to compensate for anexcessive drop due to the length of the feeder or for greater thannormal drop due For this purpose devices commonly known as boosters, bywhich the electromotive force may be raised on the desired feeder, areemployed, by the employment of which the potential of the main generatorneed not be raised above a point which is sufficient for the mainbus-bars which supply the system. My invention relates to a system ofthis kind in which the boosters are driven by electric motors suppliedfrom the distributing bus-bars. In such an organization if by reason ofan overload or any other cause the fuse or automatic circuit-breakercontrolling the motor circuit be blown the booster, being connected Withthe bus-bars through the feeder, will operate as a series motor, rapidlyaccelerating in speed until it is torn apart by centrifugal force. It isthe design of my invention to prevent such a consequence. I provide forautomatically disconnecting the booster from circuit when the motor iscut out.

The invention may be carried out in a va riety of Ways. One which I haveemployed successfully in practice consists in including in thebooster-circuit an automatic circuitbreaker provided with an auxiliarytrippingcoil energized or controlledby a local batterycircuit closedwhen the motor-circuit breaker is tripped.

Serial No. 28,652. (No model.)

included in the claims appended to this specification.

The accompanying drawing, illustrating my invention, is a diagrammaticillustration of a central-station organization, showing the preferredmeans I employ to automatically disconnect the booster from its circuitwhen the motor-circuit is opened.

In the drawing, 1 and 2 represent the busbars at the central station orother distributing-point for electrical currents.

3 represents an electrically-driven serieswound booster connectingthrough an automatic circuit-breaker L with a feeder 5.

6 represents an electric motor direct connected with the booster andsupplied from the bus-bars 1 2 through an automatic circuitbreaker 7 Thetrip of the circuit-breaker is provided with a bridging-contact 8 innormally open relation to two contacts 9 9, forming the terminals of alocal circuit, including a battery 10 or other local source of energyand a relay 11. The armature of the relay carries a bridging-contact 12,cooperating with two contacts 13 18*, forming the ter-.

minals of a branch circuit from the bus-bars 1 2, including an auxiliarytrip-coil 14 for the circuit-breaker 1 in the booster-circuit. The frameof the relay supports a pivoted arm 15, controlled by aretracting-spring 16 and carrying an elastic metallic contact 17,normally bridging two contacts 18 18 in the same branch circuit from thebus-bars, which includes the auxiliary trip-coil 14. These contacts arenormally bridged, and the arm 15 is latched with the spring undertension by a detent carried by the armature of the relay. \Vith thisorganization it will be evident that when from any cause the motor 6becomes overloaded the same effort of the coil which tripsitscircuit-breaker 7 bridges the contacts 9 9 and energizes the coil 11,thereby closing the contacts 13 13 and actuating the circuitbreaker 4:through the instrumentality of the auxiliary trip-coil 1 1. Thebridging-contact 17 is so arranged as to hold the circuit it closesclosed for a determinate interval after it is unlatched by the armatureof relay 11. This gives suflicient time to permit the auxiliarytripping-coil 14 to act upon the circuit of the booster 3, after whichthe branch circuit from the busbars is opened by the withdrawal of thecontact 17. It will also be noted that when the motor-circuit is openedthe trip-coil of circuit-breaker 7 releases its armature and opens thebattery-circuit, thereby preventing a waste of battery energy.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. The combination of an electric circuit, an automatic circuit-breakertherein, an independently-operated cut-out in another circuit, eachresponsive to a definite load, and means for tripping in sequence thecircuit-breaker after the cut-out operates.

2. The combination of an electric circuit, an automatic magneticallytripped circuitbreaker in the same, an independent automaticcircuit-breaker, each circuit-breaker being responsive to a definiteload, and means controlled by one circuit-breaker to operate in sequencethe tripping mechanism of the other after it is tripped:

3. "he combination of a plurality of automatic circuit-breakers, eachresponsive to a determinate load, and separate circuits controlledthereby, with means for operating one circuit-breaker by the opening ofthe other when tripped.

4. The combination with an electric circuit, of a dynamic source ofregulating electromotive force in series therewith, a motor foractuating said source, and means for protecting said source when themotor ceases to operate.

5. The combination with an electric circuit, of a regulable dynamicsource of regulating electromotive force in series therewith, a motorfor actuating said source, and means for protecting said source when themotor ceases to operate.

6. The combination with a booster, of an electric motor for driving thesame, a cut-out in the booster-circuit, and means for automaticallyactuating the cut-out when the motor ceases to operate.

7. The combination with a booster, of means for driving the same, acut-out in the boostercircuit, and means for actuating the cut-out whenthe driving power for the booster is withdrawn.

8. The combination with a booster, of a source of power for driving thesame, a cut-out in the booster-circuit, a controlling-circuit for thecut-out, and a current-controller in said circuit governed by the sourceof power.

9. The combination with a booster, an electric motor propelling thesame, a cut-out in the booster-circuit, a controlling-circuit for thecut-out, a circuit-controller in said circuit, and an overload-coil inthe motor-circuit governing said circuit-controller.

10. The combination of a motor driven booster, an automaticcircuit-breaker in the booster-circuit, and means for tripping thecircuit-breaker when an overload exists in the motor-circuit.

11. The combination with a booster, of a propelling electric motor,automatic circuitbreakers in the booster and motor circuitsrespectively, and auxiliary tripping devices for the booster-circuitbreaker controlled by the opening of the motor-circuit breaker.

12. The combination with a booster having its field-magnet andarmature-windings in series relation, a propelling electric motor,automatic circuit-breakers in the motor and booster circuits, and meansfor tripping the booster-circuit breaker when the motor-circuit breakeropens.

13. The combination of a motor driven booster having a series field andits motor and booster circuits and automatic circuit-breakers, withmeans interposed between the circuitbreakers and constructed to trip thecircuitbreaker of the booster in response to the actuation or blowing ofthe circuit-breaker of the motor, substantially as described.

14. In a system of electrical distribution, the combination with a mainsource of current, a booster to increase the potential of said source, apropelling electric motor for the booster, means for including the motorin circuit with a source of current, an electromagnetic circuit-breakerprovided with a switch for opening and closing the distribution-circuit,a coil of the circuit-breaker in a normally open circuit, andelectromagnetic means in the motor-circuit for energizing said coil torelease the switch.

15. In a system of electrical distribution, the combination with asource of current, of a main transmission-line receiving currenttherefrom, a booster for furnishing additional pressure to the maintransmission line, a motor for operating the booster, an electromagneticcircuit-breaker for opening the circuit through the booster, andelectromagnetic means in the motor-circuit for closing the circuitthrough the electromagnetic circuit-breaker.

16. In a system of electrical distribution, the combination with asource of current, of a maintransmission-linereceivingcurrenttherefrom,a booster for furnishing additional pressure to the maintransmission-line,a motor for operating the booster, an electromagneticcircuit-breaker for opening the booster-circuit having a windingincluded in the main transmission-line, and electromagnetic means in themotor-circuit for closing a circuit through a winding of thecircuit-breaker.

17 In a system of electrical distribution, the

combination with a source of current, of a for including the secondwinding in circuit maintransmission-linereceivingcurrenttherewith asource of current. I from, a booster for furnishing additional Inwitness whereof I have hereunto set my pressure to the maintransmission-line, amotor hand this 29th day of August, 1900.

for operating the booster, an electromagnetic EDWARD M. HEWVLETT.circuit-breaker having two windings, one in- Witnesses: cluded in themain transmission-line, and BENJAMIN B. HULL,

electromagnetic means in the motor-circuit FRED Russ.

